The research comprising this application addresses two separate but related phenomena involving bone formation. One investigation focuses on the bone formation in porous artificial tooth roots. The hypothesis of this study is that the bone growth into porous coatings on artificial tooth roots produces an interlocking bond that can serve as an efficacious attachment vehicle for stabilizing endosseous dental implants. This hypothesis is to be tested by implanting artificial tooth roots coated with porous high density polyethylene, porous polysulfone, and porous titanium in dogs and Rhesus monkeys. The tooth roots will serve as the abutments for individual free standing crowns and as abutments for bridges. Implants will be monitored clinically by measuring mobility and depth of periodontal pockets, and by assessing plaque accumulation and bleeding. Radiographs will also be recorded at regular monthly intervals. Implants and surrounding tissue recovered by sacrifice or resection will be evaluated histologically and by microradiography. Tissue specimens will be embedded in paraffin or plastic in preparation for microtomy or hard tissue grinding procedures. Histology and microradiography will be performed to evidence bone growth into the pores of the coating. A second hypothesis to be tested is that the mechanical properties of the porous coating material affects dental implant performance. Evidence supporting or negating this hypothesis is to be gained by comparison of results achieved with the artificial tooth roots (of similar design) coated with porous polyethylene, porous polysulfone, and porous titanium. A second aspect of the research in this application investigates the sequence of events associated with the induction of bone by implantation of demineralized allogeneic bone matrix in extraosseous sites. These studies will be performed in rats and rabbits, and employ histological procedures to follow the course of induction of nonosseous mesenchymal cells to osteoblasts and chondroblasts, and subsequent bone formation.